Cross web tension measurement and control

ABSTRACT

The present disclosure generally relates to systems and methods for transporting a web through a web processing apparatus. In one aspect, a web tension adjustment unit for guiding a web. The web tension adjustment unit includes a first guide roller. The first guide roller includes an adjustment unit. The web tension adjustment unit further includes one or more first non-contact sensors positioned to measure displacement data of the web at a first location. The web tension adjustment unit further includes a system controller for controlling the adjustment unit based on the measured displacement data.

CROSS-REFERENCES TO RELATED APPLICATIONS

This application claims priority to U.S. Provisional Patent Application No. 63/185,223, filed May 6, 2021, which is incorporated herein by reference in its entirety.

BACKGROUND Field

The present disclosure generally relates to systems and methods for transporting a web through a web processing apparatus.

Description of the Related Art

Web handling is a key factor when processing a continuous web. Many rollers handling hundreds of meters or even kilometers of web have to be arranged and operated in such a way that no damage, in particular unilateral thermal damage such as wrinkles, tear-offs, or the like occur in the web. However, web thickness of, for instance, plastic or metal foils can vary over the substrate width. Also, sometimes the web is wound up on a storage spool roller with a different inner tension over the width of the web.

It is undesirable that failures occur during web processing such as web coating. These failures can lead to the total stoppage of production and/or to the rejection of parts of or the entire processed web. In other words, a web guiding malfunction can be very expensive and time consuming.

Furthermore, there are considerable space constraints in current web processing apparatuses, such as a coating apparatus. In addition, in many applications the web must not be touched or guided on one side of the web at all, namely, the coated side of the web or foil. Consequently, the design of the web's route through a web processing apparatus, such as a coating apparatus, is essentially limited.

Thus, there is a need for systems and methods for monitoring and controlling a web as it travels through a processing system.

SUMMARY

The present disclosure generally relates to systems and methods for transporting a web through a web processing apparatus.

In one aspect, a web tension adjustment unit for guiding a web. The web tension adjustment unit includes a first guide roller. The first guide roller includes an adjustment unit. The web tension adjustment unit further includes one or more first non-contact sensors positioned to measure displacement data of the web at a first location. The web tension adjustment unit further includes a system controller for controlling the adjustment unit based on the measured displacement data.

Implementations can include one or more of the following. The one or more first non-contact sensors are selected from confocal laser sensors, triangulation based laser sensors, line based laser sensors, capacitance sensors, eddy current sensors, or a combination thereof. The one or more first non-contact sensors include at least two sensors arranged in a transverse direction across the web perpendicular to a travel direction of the web. The first location is between the first guide roller and a second roller, where the web is in a free span position. The one or more first non-contact sensors measure an angle of reflection of the web. The web tension adjustment unit further includes one or more second non-contact sensors positioned opposite the one or more first non-contact sensors to monitor cross-web tension to monitor a second side of the web at the first location. The adjustment unit is positioned at a first end of the first guide roller. The adjustment unit includes a motor. The system controller is a closed-loop controller and the measured displacement data is used as variable feedback signal. The system controller includes one of analogue electronics and digital electronics.

In another aspect, a web processing apparatus is provided. The web processing apparatus includes at least one web tension adjustment unit for guiding a web. The web tension adjustment unit includes a first guide roller. The first guide roller, includes an adjustment unit. The adjustment unit includes one or more first non-contact sensors positioned to measure displacement data of the web at a first location. The web tension adjustment unit further includes a system controller for controlling the adjustment unit based on the measured displacement data.

Implementations can include one or more of the following. The web processing apparatus further includes a coating unit for coating the web. The one or more first non-contact sensors are selected from confocal laser sensors, triangulation based laser sensors, line based laser sensors, capacitance sensors, eddy current sensors, or a combination thereof. The one or more first non-contact sensors include at least a first sensor and a second sensor arranged in a transverse direction across the web perpendicular to a travel direction of the web. The first location is between the first guide roller and a second roller, where the web is in a free span position. The first sensor is positioned to measure displacement of the web at the first location along the transverse direction and the second sensor is positioned to measure displacement of the web at a second location along the transverse direction. The one or more first non-contact sensors measure an angle of reflection of the web. The system controller is configured to calculate a signal for adjusting the position of the first guide roller based on the measured angle of reflection of the web such that, after adjustment, the tension of the web on both sides is identical.

In yet another aspect, a method for processing a web is provided. The method includes guiding the web using at least one web tension adjustment unit. The web tension adjustment unit includes a first guide roller including an adjustment unit. The web tension adjustment unit includes one or more first non-contact sensors positioned to measure displacement of the web at a first location. The method further includes measuring the displacement of the web at the first location. The method further includes adjusting the position of the first guide roller by moving one end of the first guide roller, wherein adjusting is based on the measured displacement of the web.

Implementations can include one or more of the following. The method further includes calculating a signal for adjusting the position of the first guide roller based on the measured displacement data, wherein after adjustment, the tension of the web on both sides is identical. The method further includes coating the web with a layer of material after adjusting the position of the first guide roller. The one or more first non-contact sensors are selected from confocal laser sensors, triangulation based laser sensors, line based laser sensors, capacitance sensors, eddy current sensors, or a combination thereof. The one or more first non-contact sensors include at least a first sensor and a second sensor arranged in a transverse direction across the web perpendicular to a travel direction of the web. The first location is between the first guide roller and a second roller, where the web is in a free span position. The first sensor is positioned to measure displacement of the web at a first location along the transverse direction and the second sensor is positioned to measure displacement of the web at a second location along the transverse direction. The one or more first non-contact sensors measure an angle of reflection of the web. The method further includes calculating a signal for adjusting the position of the first guide roller based on the measured angle of reflection of the web, wherein after adjustment, the tension of the web on both sides is identical.

In another aspect, a non-transitory computer readable medium has stored thereon instructions, which, when executed by a processor, causes the process to perform operations of the above apparatus and/or method.

BRIEF DESCRIPTION OF THE DRAWINGS

So that the manner in which the above recited features of the present disclosure can be understood in detail, a more particular description of the implementations, briefly summarized above, may be had by reference to implementations, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only typical implementations of this disclosure and are therefore not to be considered limiting of its scope, for the disclosure may admit to other equally effective implementations.

FIG. 1 illustrates a schematic cross-sectional view of a web processing apparatus according to one or more implementations of the present disclosure.

FIG. 2 illustrates a schematic cross-sectional view of a web tension adjustment unit according to one or more implementations of the present disclosure.

FIG. 3 illustrates a schematic top view of the web tension adjustment unit of FIG. 2 according to one or more implementations of the present disclosure.

FIG. 4 illustrates a schematic cross-sectional view of a roller incorporating an adjustment unit according to one or more implementations of the present disclosure.

FIG. 5 illustrates a flow diagram of a method of adjusting web tension according to one or more implementations of the present disclosure.

FIG. 6A illustrates a plot of sensor readings according to one or more implementations of the present disclosure.

FIG. 6B illustrates a plot of sensor readings according to one or more implementations of the present disclosure.

FIG. 7 illustrates a signal flow chart of adjusting web tension according to one or more implementations of the present disclosure.

FIG. 8 illustrates a schematic cross-sectional view of a web coating system incorporating a web tension adjustment unit according to one or more implementations of the present disclosure.

To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are common to the figures. It is contemplated that elements and features of one implementation may be beneficially incorporated in other implementations without further recitation.

DETAILED DESCRIPTION

The following disclosure describes roll-to-roll deposition systems, metrology systems, and methods of monitoring and adjusting web tension of a flexible substrate or web in a roll-to-roll deposition system. Certain details are set forth in the following description and in FIGS. 1 to 8 to provide a thorough understanding of various implementations of the disclosure. Other details describing well-known structures and systems often associated with web coating, coating metrology systems, and adjusting web tension of a flexible substrate or web in a roll-to-roll deposition system are not set forth in the following disclosure to avoid unnecessarily obscuring the description of the various implementations.

Many of the details, dimensions, angles and other features shown in the Figures are merely illustrative of particular implementations. Accordingly, other implementations can have other details, components, dimensions, angles and features without departing from the spirit or scope of the present disclosure. In addition, further implementations of the disclosure can be practiced without several of the details described below.

For the purposes of describing the geometry of and movement of the system, Cartesian coordinates x, y, and z are used. As used herein, movement along the x-direction can refer to both movement along the +x and −x directions. As used herein, movement along the y-direction can refer to movement along the +y and −y directions. As used herein, movement along the z-direction can refer to movement along the +z and −z directions.

Implementations described herein will be described below in reference to a roll-to-roll coating system, such as TopMet™, SmartWeb™, TopBeam™, all of which are available from Applied Materials, Inc. of Santa Clara, Calif. Other tools capable of performing roll-to-roll processing can also be adapted to benefit from the implementations described herein. The apparatus description described herein is illustrative and should not be construed or interpreted as limiting the scope of the implementations described herein. In addition, the implementations described herein are applicable to a flexible substrate having a coating on a single side or a flexible substrate having a coating on opposing sides or a “dual-sided” coating.

It is noted that while the particular substrate on which some implementations described herein can be practiced is not limited, it is particularly beneficial to practice the implementations on flexible substrates, including for example, web-based substrates, panels and discrete sheets. The substrate can also be in the form of a foil, a film, or a thin plate.

It is also noted here that a flexible substrate or web as used within the implementations described herein can typically be characterized in that it is bendable. The term “web” can be synonymously used to the term “strip,” the term “flexible substrate,” or the like. For example, the web as described in implementations herein can be a foil. Synonyms of the term “web” are strip, foil, flexible substrate or the like. Typically, a web includes a continuous sheet of thin and flexible material. Examples of web materials include metals, plastics, paper, or the like. A web as understood herein is typically a three dimensional solid body. The thickness of the web as understood herein can be less than 1 mm, more typically less than 500 mm or even less than 10 mm. A web as understood herein can have a width of at least 0.5 m, more typically at least 1 m or even at least 4 m. A web as understood herein has typically a length of at least 1 km, 25 km or even 60 km.

It is further noted that in some implementations where the substrate is a vertically oriented substrate, the vertically oriented substrate can be angled relative to a vertical plane. For example, in some implementations, the substrate can be angled from between about 1 degree to about 20 degrees from the vertical plane. In some implementations where the substrate is a horizontally oriented substrate, the horizontally oriented substrate can be angled relative to a horizontal plane. For example, in some implementations, the substrate can be angled from between about 1 degree to about 20 degrees from the horizontal plane. As used herein, the term “vertical” is defined as a major surface or deposition surface of the flexible conductive substrate being perpendicular relative to the horizon. As used herein, the term “horizontal” is defined as a major surface or deposition surface of the flexible conductive substrate being parallel relative to the horizon.

It is further noted that in the present disclosure, a “roll” or a “roller” can be understood as a device, which provides a surface, with which a substrate (or a part of a substrate) can be in contact during the presence of the substrate in the processing system. At least a part of the “roll” or “roller” as referred to herein can include a circular-like shape for contacting the substrate to be processed or already processed. In some implementations, the “roll” or “roller” can have a cylindrical or substantially cylindrical shape. The substantially cylindrical shape can be formed about a straight longitudinal axis or can be formed about a bent longitudinal axis. According to some implementations, the “roll” or “roller” as described herein can be adapted for being in contact with a flexible substrate. For example, a “roll” or “roller” as referred to herein can be a guiding roller adapted to guide a substrate while the substrate is processed (such as during a deposition process) or while the substrate is present in a processing system; a spreader roller adapted for providing a defined tension for the substrate to be coated; a deflecting roller for deflecting the substrate according to a defined travelling path; a processing roller for supporting the substrate during processing, such as a process drum, for example, a coating roller or a coating drum; an adjusting roller, a supply roll, a take-up roll or the like. The “roll” or “roller” as described herein can comprise a metal. In one implementation, the surface of the roller device, which is to be in contact with the substrate, can be adapted for the respective substrate to be coated. Further, it is to be understood that according to some implementations, the rollers as described herein can be mounted to low friction roller bearings, particularly with a dual bearing roller architecture. Accordingly, roller parallelism of the transportation arrangement as described herein can be achieved and a transverse substrate “wandering” during substrate transport can be eliminated.

Variations in tension along the web during processing due to misalignment of rollers in the web system can lead to wrinkles and other deformities in the processed web, which can ruin the processed web. One way of adjusting web tension in the chamber is to shut down the web system, open the web system, and physically adjust the rollers. However, this can lead to significant downtime to the web system, which increases the cost of ownership. In addition, these deformities in the web may not be detected until after the entire web is processed. This can lead to scrapping the processed web, which increases material costs. Thus, it would be advantageous to be able to monitor tension in the web in-situ during processing and dynamically adjust web tension in response to the monitored tension without opening the system.

In addition, current optical monitoring systems used in web systems may have a small depth of field, for example, a depth of field in the range of +/−20 μm. This means that the web under investigation should not vary position, for example, by fluttering, by more than +/−20 μm along the optical path of the light beam. It is particularly difficult to reliably measure optical transmission properties of a flexible substrate during transport thereof. For example, flexible substrates may be prone to fluttering in a direction perpendicular to the substrate transportation path, in particular at portions of the substrate where the substrate is not supported on a substrate support. Further, flexible substrates are typically thin and delicate so that such substrates may flutter by more than 20 μm at unsupported positions. This web flutter typically limits the types of distances measurement sensors that can be used to monitor the flexible substrate. For example, typically triangulation based sensors are not used for dual-sided measurements due to web fluttering.

In the processes of web coating there are several metrology techniques that are used for measuring thickness. Some of these techniques suffer from web flutter induced errors and make their use more difficult. Some implementations of the present disclosure take the opposite approach and use the sensitivity to flutter as the measurement of interest and use that as a non-contact proxy for the local tension in the web. Any suitable sensor metrology that has sensitivity to sample angle can be used. For example, triangulation laser displacement, capacitance, and eddy current can be used. Basically any signal sensitive to flutter can be reused either on an uncoated part of the web or a coated section where the variation in thickness occurs at a much different frequency than the signal from flutter. If both sources of variation occur, they can be partitioned mathematically with high and low pass filters to extract the related thickness and flutter/web tension information.

In some implementations of the present disclosure, cross web tension is measured in real-time using a non-contact sensor to calculate web angle. The measurement of web angle can be driven back into a control system to adjust the parallelism of the rollers enabling the use of various optical sensors such as laser sensors to monitor the web. Laser based triangulation distance sensors are sensitive to the angle of the web presentation. The angle of the web is a function of the tension and the filtering mechanism. For webs of known and stable thickness, the shift in apparent thickness is now a manifestation of the web angle locally. That angle is a function of the tension of the web path at that point and if the locations are chosen at both web edges where no coating occurs, then the cross web tension can be measured in real-time. This measurement can then be driven back into a control system to correct the web tension by adjusting the parallelism of the rollers.

In some implementations of the present disclosure, the non-contact sensor is selected from confocal laser sensors, triangulation based laser sensors, line based laser sensors, capacitance sensors, eddy current sensors, or a combination thereof.

FIG. 1 illustrates a schematic cross-sectional view of a web processing system 100 including a web processing apparatus 110 according to one or more implementations of the present disclosure. The web processing apparatus 110 includes a web tension adjustment unit 120. The web processing apparatus 110 can further include one or more coating units (not shown) where a web 130 is fed for being coated with one or more layers. Further, a web storage spool 140 is shown where the web 130 is coiled. Typically, the web 130 on the web storage spool 140 is unprocessed. Alternatively to the shown implementation, the web storage spool 140 may be positioned within the web processing apparatus 110 (see, for instance, the implementation illustrated in FIG. 8). In some implementations described herein, the web processing apparatus 110 is operated at vacuum conditions, for example, at pressures below 10 mbar or even below 1 mbar. In other implementations, the web processing apparatus 110 is operated at atmospheric conditions.

As shown in FIG. 1, the web 130 enters the web processing apparatus 110 via an inlet port 150, such as a first seal. The processed web 160 is guided out of the web processing apparatus 110 through the outlet port 170, such as a second seal, and may be spooled up on wind-up spool 180. Alternatively to the implementation shown in FIG. 1, the wind-up spool for storing the processed web may be positioned within the web processing apparatus 110 (see, for instance, the implementation illustrated in FIG. 8). Consequently, in some implementations, the wind-up spool can be configured to operate in vacuum conditions.

Typically, the web processing apparatus 110 includes one, two, three, or more web tension adjustment units 120 according to the present disclosure.

The web processing system 100 further includes a system controller 190 operable to control various aspects of the web processing system 100. The system controller 190 facilitates the control and automation of the web processing system 100 and can include a central processing unit (CPU), memory, and support circuits (or I/O). Software instructions and data can be coded and stored within the memory for instructing the CPU. The system controller 190 can communicate with one or more of the components of the web processing system 100 via, for example, a system bus. A program (or computer instructions) readable by the system controller 190 determines which tasks are performable on a substrate such as the web 130. In some aspects, the program is software readable by the system controller 190, which can include code for monitoring processing conditions, controlling the web processing apparatus 110, and/or controlling the web tension adjustment unit 120. Although a single system controller, the system controller 190 is shown, it should be appreciated that multiple system controllers can be used with the aspects described herein.

A typical application of a web guide control unit or a web processing apparatus as disclosed herein is high vacuum web film deposition. For instance, in some energy storage device applications, a thin layer of lithium metal can be deposited over the web serving as a pre-lithiation layer for underlying anode or cathode materials. A further application of a web tension adjustment unit or a web processing apparatus as disclosed herein involves deposition of a protective layer on a packaging substrate like thin plastic, paper, or metal foil. Thin metal or oxide films may be deposited on the packaging substrate for creating a moisture or oxygen barrier promoting freshness and extending the shelf life of the consumer products which use these films.

According to an implementation of the present disclosure, the web 130 is fed to the web processing apparatus 110 from a web supply such as the web storage spool 140. Typical lengths of the web on the coil are in the range between 500 meters and 60 kilometers. In some implementations, the web 130 is fed to the web processing apparatus 110 from a previous web processing apparatus (not shown). Generally, and not limited to the present implementation, two, three, or more of the web processing apparatuses as disclosed herein may be positioned next to each other so that a web is consecutively lead through all of these web processing apparatuses.

Not limited to implementation, typical guiding velocities are in the range of between 0.01 meter per minute and 20 meter per second (m/s). Different processing operations may be performed in the web processing apparatus 110, such as cleaning, coating, in particular sputtering, cooling, heating, or structuring the web.

After the web has been processed in the web processing apparatus 110, the processed web 160 exits the web processing apparatus 110 at the outlet port 170. The processed web 160 can be fed to a second processing unit or guided out for storage, such as shown in FIG. 1 by the wind-up spool 180. Notably, the web processing system, web processing apparatus, and methods as disclosed herein particularly allow for winding-up the web on a spool in a straight manner, thus avoiding an asymmetric layer stack on the wind-up spool.

A web tension adjustment unit and a web processing apparatus as described herein may be used for guiding a web in various applications. The web processing apparatus as described herein is particularly suitable for coating webs such as a metal web, in particular a copper or aluminum web, and thin plastic webs. Thin web in this context is meant to be understood as having a thickness of between 1 m and 200 m, in particular between 30 μm and 140 μm.

FIG. 2 illustrates a schematic cross-sectional view of the web tension adjustment unit 120 according to one or more implementations of the present disclosure. FIG. 3 illustrates a schematic top view of the web tension adjustment unit 120 of FIG. 2 according to one or more implementations of the present disclosure. The web tension adjustment unit 120 includes a first roller 210 and a second roller 220 for guiding a substrate, such as the web 130. The first roller 210 and/or the second roller 220 can be guide rollers. The web tension adjustment unit 120 further includes one or more first non-contact sensors 230 a-230 d (collectively 230) and optionally one or more second non-contact sensors 240. The one or more first non-contact sensors 230 and/or the one or more second non-contact sensors 240 can either be free-standing or positioned in a module. As is shown in FIG. 2, the web 130 is carried and conveyed from the first roller 210 to the second roller 220 along a substrate transportation path T.

In some implementations, the one or more first non-contact sensors 230 are provided in a position between the first roller 210 and the second roller 220. If present, the one or more second non-contact sensors 240 are also provided in a position between the first roller 210 and the second roller 220. The one or more second non-contact sensors 240 can be positioned opposite the one or more first non-contact sensors 230. The one or more first non-contact sensors 230 can be positioned to face a first side or “front side” of the web 130 and the one or more second non-contact sensors 240 can be positioned to face a second side or “backside” of the web 130. The area between the first roller 210 and the second roller 220, where the web 130 is not supported on a substrate support surface, for example a surface of a roller, may also be referred to as “free span” or “free span position.” It is indicated that the web 130 can flutter at the “free span position,” so that the optical measurement may be negatively affected. For example, the inspected portion of the web 130 can move out of the focus of the light beam in a direction perpendicular to the substrate transport direction “T”. This change in the angle of reflection during fluttering changes the angle of reflection of the web, which can be used to identify a change in local tension of the web. This change in local tension can be communicated to and/or calculated by the system controller 190 and then used to adjust the parallelism of the first roller 210 and/or the second roller 220.

In some implementations, as shown in FIG. 3, the one or more first non-contact sensors 230 includes a plurality of first non-contact sensors 230 a-230 d that are positioned side-by-side along the transverse direction, which is perpendicular to the travel direction “T.” Although four first non-contact sensors are shown in FIG. 3, any suitable number of first non-contact sensors can be used. For example, in some implementations, a single non-contact sensor configured to move over the web 130 along the transverse direction is used in place of the plurality of non-contact sensors. Positioning the plurality of first non-contact sensors 230 a-230 d along the transverse direction allows the non-contact sensors to monitor across the width of the web 130. Any suitable non-contact sensor that has sensitivity to the angle of the web (e.g., fluttering of the web). The one or more first non-contact sensors 230 a-230 d can include any number of laser-based triangulation sensors, interferometers, image sensors, Eddy Current Sensors (ECS), capacitance sensors, and/or thickness sensors. Examples of suitable non-contact sensors include laser-based triangulation sensors, for example, Keyence and Micro-Epsilon LVDT interferometers. Examples of laser profilometers that can be used with the implementations described herein include the Keyence LJ-X8020, which can measure anode edge definition within a 7.5 mm width and has edge thickness (Z-axis) and straightness (X-axis) repeatability within 0.3 μm for both axes, and the Keyence CL-PT010, which can measure anode edge definition within a 10 mm width and has edge thickness and straightness repeatability within 0.2 μm for both axes.

FIG. 4 illustrates a schematic cross-sectional view of a guide roller 400 incorporating an adjustment unit according to one or more implementations of the present disclosure. The guide roller 400 can be, for example, at least one of the first roller 210 and the second roller 220 used in the web tension adjustment unit 120. The guide roller 400 is typically mounted to a shaft 410. As used herein, the term shaft shall include any support of the guide roller 400 that may be either rotatable, for example, or may constitute a static axis about which the roller rotates.

The web 130 is guided by the guide roller 400. The web 130 can generally be unprocessed or have already undergone one or more processing operations. In particular, the web tension adjustment unit 120 of the present disclosure is not exclusively limited to use in web processing apparatuses. For example, the web tension adjustment unit 120 can also be implemented in manufacturing plants where web transport is used.

For the purpose of illustration, the guide roller 400 is shown as being mounted on a frame 420. The frame 420 may be any unit capable of supporting the guide roller 400. Notably, it is possible, but not necessary, that the frame 420 on both sides of the guide roller 400 belongs to a one-piece frame. Typical diameters of guide rollers used in the present subject-matter are between 65 mm and 300 mm.

The alignment of the guide roller 400 is adjusted using a roller adjustment unit 430 a, 430 b (collectively 430). In some implementations, a single adjustment unit is provided. For example, either the roller adjustment unit 430 a or the roller adjustment unit 430 b is present. The roller adjustment unit 430 is typically placed at the first end 440 or the second end 450 of the guide roller 400. For example, the roller adjustment unit 430 a can be placed at the first end 440. The roller adjustment unit 430 b can be placed at the second end 450 of the guide roller 400. It is also possible that two adjustment units are provided, typically each at the first end 440 and the second end 450 of the guide roller 400, such as each on one end of the guide roller 400. For instance, as exemplarily illustrated in FIG. 4, the roller adjustment unit 430 b is placed adjacent to the second end 450.

In some implementations, the roller adjustment unit 430 is capable of at least one of movement along the x-direction (+x/−x), movement along the y-direction (+y/−y), and movement along the z-direction (+z/−z). Thus, each of the first end 440 and the second end 450 of the guide roller 400 can be independently adjustable along at least one of the x-direction (e.g., +x/−x), the y-direction (e.g., +y/−y), and the z-direction (e.g., +z/−z).

In principle, the roller adjustment unit 430 can be applied for alignment of the guide roller 400 to avoid transversal tension acting on the web 130. Typically, the roller adjustment unit 430 of the present disclosure is particularly useful for compensating different coiling strengths at the guide roller 400, and consequently at all equipment subsequent to the guide roller 400. Different coiling strength is most typically a result of different thickness of the web along its width. This can generally result in tilted feeding and, subsequently, varying contact between guiding rollers and the web 130, which can go along with thermal complications.

In some implementations of the present disclosure, the guide roller 400 is a cooling or heating roller. Typically, there are further rollers positioned downstream and/or upstream of the guide roller 400. Other processing operations, such as cleaning or coating, may be undertaken before (i.e., upstream) the guide roller 400 or after (i.e., downstream) the guide roller 400.

Not limited to any implementation of the present disclosure, the data measured by the one or more first non-contact sensors 230 can be used for monitoring the alignment of the guide roller 400 and adjusting the alignment of the guide roller 400 by moving one end of the guide roller 400. Thus, the alignment of the guide roller 400 as compared to one or more of the horizontal and vertical direction is changed. If only one roller adjustment unit 430 is provided at one end of the guide roller 400, the other end of the guide roller 400 remains at a constant position.

The guide roller 400 is typically moved in a dimension that corresponds to the dimension in which the force caused by the web tension acts on the shaft 410 of the guide roller 400. Herein, the feature “movement in a dimension” or “measurement in a dimension,” respectively, shall refer to a movement or measurement, respectively, in a direction and/or its opposite direction. For instance, the double-headed arrow 460 shown in FIG. 4, illustrates one dimension. In some implementations described herein, the tension is measured in the same dimension as the guide roller is moved.

In some implementations, the roller adjustment unit 430 includes an actuator, such as a motor, for moving one end of the guide roller 400. Notably, this is not limited to the implementation of FIG. 4, and the one or more roller adjustment units 430 of all implementations described herein may be provided with an actuator, such as a motor. For instance, in one example, the motor may be a linear motor. In another example, the motor can be capable of movement along at least one of the x-direction, the y-direction, and the z-direction. As indicated by the arrow 460, the motor is capable of moving the end of the guide roller 400 up and down in the shown perspective of this page. The motor is also capable of moving the guide roller 400 perpendicular to the plane of the page.

In some implementations, not limited to the implementation of FIG. 4, the movement directions of the roller adjustment unit 430 correspond to the measurement directions of the calculated tension. That is, as in the illustration of FIG. 4, the system controller 190 is typically configured to calculate tension at the guide roller in the same direction as the adjustment unit is configured to move the guide roller. For instance, in the implementation of FIG. 4, the direction indicated by the arrow 350 may correspond both to the movement directions of the adjustment unit 310, and the measurement directions of the calculated tension.

Different motors can be used in the roller adjustment unit 430 of the present disclosure. Typically, the actuator for adjustment is either an electrical or a hydraulic motor. Rails (not shown) or the like may be provided at the frame 420 along which the roller adjustment unit 430 moves the respective side(s) of the guide roller 400.

FIG. 5 illustrates a flow diagram of a method 500 of adjusting web tension according to one or more implementations of the present disclosure. The method 500 can be performed using a web tension adjustment unit, for example, the web tension adjustment unit 120. The web tension adjustment unit 120 can be positioned in a coating system, such as the web coating system 800 depicted in FIG. 8. FIG. 6A illustrates a plot 600 of sensor readings (602, 604, 606, and 608) according to one or more implementations of the present disclosure. FIG. 6B illustrates a plot 620 of sensor readings (622, 624, 626, and 628) according to one or more implementations of the present disclosure.

At operation 510, the web 130 is transported along the substrate transportation path “T”.

At operation 520, during transfer of the web 130 past the one or more first non-contact sensors 230, the one or more non-contact sensors, emit, for example, a laser, which monitors the height, position, or distance of the web relative to the one or more first non-contact sensors 230. Referring to FIG. 6A, plot 600 depicts the sensor readings for four one or more first non-contact sensors 230 arranged in a transverse direction across the web 130. For example, the sensor reading 602 corresponds to the first non-contact sensor 230 a, which monitors the web at a first location along the transverse direction. The sensor reading 604 corresponds to the second non-contact sensor 230 b, which monitors the web at a second location along the transverse direction. The sensor reading 606 corresponds to the third non-contact sensor 230 c, which monitors the web at a third location along the transverse direction. The sensor reading 608 corresponds to the fourth non-contact sensor 230 d, which monitors the web at a third location along the transverse direction. As shown in the plot 600, the fourth non-contact sensor 230 d detects a problem 610 or anomaly, which can be caused by fluttering of the web 130 or displacement of the web due to a misalignment of one of the rollers, for example, the second roller 220.

At operation 530, in response to detection of the problem 610, the system controller 190 can initiate maintenance/realignment of the rollers to adjust tension on the web 130 to achieve a more uniform web tension. In some implementations, the rollers are aligned dynamically in real-time to adjust the tension of the web 130. Referring to FIG. 6B, plot 620 depicts the sensor readings for the four one or more first non-contact sensors 230 arranged in a transverse direction across the web 130 after correction of the web tension. For example, the sensor reading 622 corresponds to the first non-contact sensor 230 a, the sensor reading 624 corresponds to the second non-contact sensor 230 b, the sensor reading 626 corresponds to the third non-contact sensor 230 c, and the sensor reading 628 corresponds to the fourth non-contact sensor 230 d. As shown in the plot 620, the sensor reading 628 of the fourth non-contact sensor 230 d illustrates that the problem 610 has been corrected to demonstrate a smoother reading 630 indicating that the rollers have been realigned and tension on the web 130 is more uniform.

FIG. 7 illustrates a signal flow chart 700 for a web tension adjustment unit according to one or more implementations of the present disclosure. The signal flow chart 700 for the web tension adjustment unit includes a closed-loop controller based on a negative feedback 710 of a transversal tension measurement. The closed-loop system maintains an output of the controlled system, e.g. the feedback signal 720, equal to a set point 730 value by using previous values of the feedback signal 720 and a control signal 740 fed to the controlled system which is an output of the system controller 190 itself. The main elements of the signal flow chart 700 are the system controller 190, the guide roller 400, and the one or more first non-contact sensors 230, which constitute the web tension adjustment unit 120 according to implementations of the present disclosure. The tension difference in the web can be calculated based on monitoring by at least two non-contact sensors positioned along the transverse direction of the web is the feedback signal 720. In some implementations, the tension difference in the web can also be calculated based on monitoring by a single sensor configured to travel along the transverse direction of the web. The tension calculated based on monitoring of a first location along the transverse direction can be compared with the tension calculated based on monitoring of a second location along the transverse direction to determine whether the tension of the web is uniform or non-uniform. If the tension is non-uniform, the guide roller 400 can be adjusted to correct the tension of the web.

In some implementations, the set point 730 at the controller has a null value in order to compensate for tension differences which correspond to transversal tensions acting on the web. Therefore, in some implementations, an error 731 corresponds to the tension difference measurement, i.e. the feedback signal 720. In some implementations, the system controller 190 compensates for deviations from zero of the error 731 using the roller adjustment unit 430 of the guide roller 400. Typically, this error 731 compensation translates to an adjustment (i.e., movement) of the shaft 410 of the guide roller 400. Therefore, the control signal 740, e.g. the controller output, typically corresponds to the instruction to the roller adjustment unit 430 of how much the respective end of the guide roller 400 shall be moved.

In principle, different control approaches can be implemented in the system controller 190. In some implementations, a linear control approach is implemented in the system controller 190 choosing from: proportional, integral and derivative (PID) control; proportional and integral (PI) control; proportional and derivative (PD) control; and proportional (P) control. However, also other advanced controls using non-linear control approaches can be implemented in implementations of the present disclosure, for example, adaptive gain, dead-time compensation, fuzzy logic, neural networks, or feed-forward control. Controllers implemented in the present application can be analogue or digital interfaces including compatibility with transistor-transistor logic (TTL). Typically, digital interfaces work in a discrete manner where the values for the adjustment unit are refreshed after a certain and fixed time period. Other special features can be present in controllers of the present disclosure such as self-tuning, signal computation or filtering, or built-in indicators.

FIG. 8 illustrates a schematic cross-sectional view of a web coating system 800 incorporating a web tension adjustment unit according to one or more implementations of the present disclosure. The web coating system 800 includes a first web tension adjustment unit 812 a and optionally a second web tension adjustment unit 812 b. The first web tension adjustment unit 812 a and the second web tension adjustment unit 812 b can be the web tension adjustment unit 120 previously described herein.

The web coating system 800 can be a SMARTWEB® system, manufactured by Applied Materials, adapted for depositing coatings on webs according to the implementations described herein. The web coating system 800 includes a common processing environment 801 in which some or all of the processing actions for coating a web can be performed. In one example, the common processing environment 801 is operable as a vacuum environment. In another example, the common processing environment 801 is operable as an inert gas environment.

The web coating system 800 is constituted as a roll-to-roll system including an unwinding module 802 for supplying a continuous flexible substrate, a processing module 804 for processing the continuous flexible substrate, and a winding module 808 for collecting the continuous flexible substrate. The processing module 804 includes a chamber body 805 that defines the common processing environment 801.

In some implementations, the processing module 804 includes a plurality of processing modules 810, 820, 830, and 840 arranged in sequence, each configured to perform one processing operation to the web 130 of material. In one example, as depicted in FIG. 8, the processing modules 810-840 are radially disposed about a coating drum 855. In addition, arrangements other than radial are contemplated. For example, in another implementation, the processing modules 810-840 can be positioned in a linear configuration. Each processing module 810-840 includes a deposition source. The compartments can be closed or isolated relative to adjacent compartments except for a narrow opening allowing for deposition over the coating drum 855.

In some implementations, the processing modules 810-840 are stand-alone modular sub-chambers wherein each processing module is structurally separated from the other modular sub-chambers. Therefore, each of the stand-alone modular sub-chambers, can be arranged, rearranged, replaced, or maintained independently without affecting each other. Although four processing modules 810-840 are shown, it should be understood that any number of processing modules could be included in the web coating system 800. For example, the web coating system 800 can include, but is not limited to, 3, 4, 6, or 12 processing modules.

The processing modules 810-840 can include any suitable structure, configuration, arrangement, and/or components that enable the web coating system 800 to deposit a coating according to implementations of the present disclosure. For example, but not limited to, processing modules 810-840 may include suitable deposition systems including coating sources, power sources, individual pressure controls, deposition control systems, and temperature control. In some implementations, the processing modules 810-840 are provided with individual gas supplies. The processing modules 810-840 are typically separated from each other for providing good gas separation.

Each of the processing modules 810-840 can include one or more deposition sources. Generally, the one or more deposition sources as described herein can include at least one of an electron beam source, CVD sources, PECVD sources, and various PVD sources. Exemplary PVD sources include sputtering sources, electron beam evaporation sources, and thermal evaporation sources. In one implementation, the evaporation source is a lithium (Li) source. Further, the evaporation source can also be an alloy of two or more metals. The material to be deposited (e.g., lithium) can be provided in a crucible. The lithium can be evaporated, for example, by thermal evaporation techniques or by electron beam evaporation techniques.

In some implementations, the processing modules 810-840 are configured to process both sides of the web 130. Although the web coating system 800 is configured to process the web 130, which is horizontally oriented, the web coating system 800 can be configured to process substrates positioned in different orientations, for example, the web 130 can be vertically oriented. In some implementations, the web 130 is a flexible conductive substrate. In some implementations, the web 130 includes a conductive substrate with one or more layers formed thereon. In some implementations, the conductive substrate is a copper substrate.

In some implementations, the web coating system 800 includes a reel-to-reel system with a common take-up reel 854 positioned in the winding module 808, the coating drum 855 positioned in the processing module 804, and a feed reel 856 positioned in the unwinding module 802. The take-up reel 854, the coating drum 855, and the feed reel 856 can be individually heated. The take-up reel 854, the coating drum 855 and the feed reel 856 can be individually heated using an internal heat source positioned within each reel or an external heat source. The web coating system 800 can further include one or more auxiliary transfer rollers 853 a, 853 b, 853 c, 853 d, 853 e, 853 f positioned between the take-up reel 854, the coating drum 855, and the feed reel 856. According to one aspect, at least one of the one or more auxiliary transfer reels 853 a-853 f, the take-up reel 854, the coating drum 855, and the feed reel 856 can be driven and rotated, by a motor.

In some implementations, the first web tension adjustment unit 812 a is positioned upstream from the plurality of processing modules 810-840 and upstream from the feed reel 856. For example, as shown in FIG. 8, the first web tension adjustment unit 812 a includes the one or more first non-contact sensors 230 a and optionally the one or more second non-contact sensors 240 positioned adjacent to a free-span portion of the web 130 between the auxiliary transfer rollers 853 b and 853 c. In some implementations, as depicted in FIG. 8, the first web tension adjustment unit 812 a is positioned in the processing module 804. Other locations for the first web tension adjustment unit 812 a are also contemplated. In one example, the first web tension adjustment unit 812 a can be positioned in the unwinding module 802. In another example, the first web tension adjustment unit 812 a is positioned in a separate module and the separate module is positioned between the unwinding module 802 and the processing module 804.

In some implementations, the second web tension adjustment unit 812 b is positioned downstream from the plurality of processing modules 810-840 and upstream from the take-up reel 854. For example, as shown in FIG. 8, the second web tension adjustment unit 812 b includes the one or more first non-contact sensors 230 e and optionally the one or more second non-contact sensors 240 e positioned adjacent to a free-span portion of the web 130 between the auxiliary transfer rollers 853 d and 853 e. In some implementations, as depicted in FIG. 8, the second web tension adjustment unit 812 b is positioned in the processing module 804. Other locations for the second web tension adjustment unit 812 b are also contemplated. In one example, the second web tension adjustment unit 812 b can be positioned in the winding module 808. In another example, the second web tension adjustment unit 812 b is positioned in a separate module and the separate module is positioned between the processing module 804 and the winding module 808.

The web coating system 800 includes the feed reel 856 and the take-up reel 854 for moving the web 130 past the different processing modules 810-840. In operation, the web 130 is unwound from the feed reel 856 as indicated by the substrate travel direction shown by arrow “T.” The web 130 can be guided via the one or more auxiliary transfer reels 853 a-853 f (collectively 853). At least one of the one or more auxiliary transfer reels 853 a-853 f can be the guide roller 400. The tension of the traveling web 130 can be adjusted using the first web tension adjustment unit 812 a and/or the second web tension adjustment unit 812 b as described herein.

After uncoiling from the feed reel 856 and traveling over the auxiliary transfer roller 853 b, the web 130 is then moved past the first web tension adjustment unit 812 a. If the first web tension adjustment unit 812 a detects an anomaly in the tension of the web 130, at least one of auxiliary transfer rollers 853 b and 853 c are adjusted in response to make the tension on the web more uniform.

Implementations can include one or more of the following potential advantages. The resolution and convenience provided by laser sensors can be used to enable dual-sided simultaneous measurement. Roller parallelism of the transportation arrangement as described herein can be achieved and a transverse substrate “wandering” during substrate transport can be eliminated. Downtime in web-based processing systems can be reduced, which increases the cost of ownership. Deformities in the web can be detected during processing and corrections in response to the deformities can be made dynamically during processing. Tension in the web can be monitored in-situ during processing and web tension can be dynamically adjusted in response to the monitored tension without opening the system.

Embodiments Listing

The present disclosure provides, among others, the following embodiments, each of which can be considered as optionally including any alternate embodiments:

Clause 1. A web tension adjustment unit for guiding a web, the web tension adjustment unit, comprising:

a first guide roller, wherein the first guide roller, comprises:

-   -   an adjustment unit;

one or more first non-contact sensors positioned to measure displacement data of the web at a first location; and

a system controller for controlling the adjustment unit based on the measured displacement data.

Clause 2. The web tension adjustment unit according to Clause 1, wherein the one or more first non-contact sensors are selected from confocal laser sensors, triangulation based laser sensors, line based laser sensors, capacitance sensors, eddy current sensors, or a combination thereof.

Clause 3. The web tension adjustment unit of Clause 1 or Clause 2, wherein the one or more first non-contact sensors include at least two sensors arranged in a transverse direction across the web perpendicular to a travel direction of the web.

Clause 4. The web tension adjustment unit of Clause 3, wherein the first location is between the first guide roller and a second roller, where the web is in a free span position.

Clause 5. The web tension adjustment unit of Clause 4, wherein the one or more first non-contact sensors measure an angle of reflection of the web.

Clause 6. The web tension adjustment unit of any one of Clauses 1-5, further comprising one or more second non-contact sensors positioned opposite the one or more first non-contact sensors to monitor cross-web tension to monitor a second side of the web at the first location.

Clause 7. The web tension adjustment unit of any one of Clauses 1-6, wherein the adjustment unit is positioned at a first end of the first guide roller.

Clause 8. The web tension adjustment unit of any one of Clauses 1-7, wherein the adjustment unit comprises a motor.

Clause 9. The web tension adjustment unit of any one of Clauses 1-8, wherein the system controller is a closed-loop controller, and the measured displacement data is used as variable feedback signal.

Clause 10. The web tension adjustment unit of Clause 9, wherein the system controller comprises one of analogue electronics and digital electronics.

Clause 11. A web processing apparatus, comprising:

at least one web tension adjustment unit for guiding a web, the web tension adjustment unit, comprising:

a first guide roller, wherein the first guide roller, comprises:

-   -   an adjustment unit;

one or more first non-contact sensors positioned to measure displacement data of the web at a first location; and

a system controller for controlling the adjustment unit based on the measured displacement data.

Clause 12. The web processing apparatus of Clause 11, further comprising a coating unit for coating the web.

Clause 13. The web processing apparatus of Clause 11 or Clause 12, wherein the one or more first non-contact sensors are selected from confocal laser sensors, triangulation based laser sensors, line based laser sensors, capacitance sensors, eddy current sensors, or a combination thereof.

Clause 14. The web processing apparatus of any one of Clauses 11-13, wherein the one or more first non-contact sensors include at least a first sensor and a second sensor arranged in a transverse direction across the web perpendicular to a travel direction of the web.

Clause 15. The web processing apparatus of Clause 14, wherein the first location is between the first guide roller and a second roller, where the web is in a free span position.

Clause 16. The web processing apparatus of Clause 14 or Clause 15, wherein the first sensor is positioned to measure displacement of the web at the first location along the transverse direction and the second sensor is positioned to measure displacement of the web at a second location along the transverse direction.

Clause 17. The web processing apparatus of any one of Clauses 11-16, wherein the one or more first non-contact sensors measure an angle of reflection of the web.

Clause 18. The web processing apparatus of Clause 17, wherein the system controller is configured to calculate a signal for adjusting a position of the first guide roller based on the measured angle of reflection of the web such that, after adjustment, the tension of the web on both sides is identical.

Clause 19. A method for processing a web, comprising:

guiding the web using at least one web tension adjustment unit, wherein the web tension adjustment unit comprises:

-   -   a first guide roller comprising an adjustment unit; and     -   one or more first non-contact sensors positioned to measure         displacement of the web at a first location;

measuring the displacement of the web at the first location to provide measured displacement data of the web; and

adjusting a position of the first guide roller by moving one end of the first guide roller, wherein adjusting is based on the measured displacement of the web.

Clause 20. The method of Clause 19, further comprising calculating a signal for adjusting the position of the first guide roller based on the measured displacement data of the web, wherein after adjustment, the tension of the web on both sides is identical.

Clause 21. The method of Clause 19 or Clause 20, further comprising coating the web with a layer of material after adjusting the position of the first guide roller.

Clause 22. The method of any one of Clauses 19-21, wherein the one or more first non-contact sensors are selected from confocal laser sensors, triangulation based laser sensors, line based laser sensors, capacitance sensors, eddy current sensors, or a combination thereof.

Clause 23. The method of any one of Clauses 19-22, wherein the one or more first non-contact sensors comprises at least a first sensor and a second sensor arranged in the transverse direction across the web perpendicular to a travel direction of the web.

Clause 24. The method of Clause 23, wherein the first location is between the first guide roller and a second roller, where the web is in a free span position.

Clause 25. The method of Clause 24, wherein the first sensor is positioned to measure displacement of the web at a first location along the transverse direction and the second sensor is positioned to measure displacement of the web at a second location along the transverse direction.

Clause 26. The method of any one of Clauses 19-25, wherein the one or more first non-contact sensors measure an angle of reflection of the web.

Clause 27. The method of Clause 26, further comprising calculating a signal for adjusting the position of the first guide roller based on the measured angle of reflection of the web, wherein after adjustment, the tension of the web on both sides is identical.

Implementations and all of the functional operations described in this specification can be implemented in digital electronic circuitry, or in computer software, firmware, or hardware, including the structural means disclosed in this specification and structural equivalents thereof, or in combinations of them. Implementations described herein can be implemented as one or more non-transitory computer program products, i.e., one or more computer programs tangibly embodied in a machine readable storage device, for execution by, or to control the operation of, data processing apparatus, e.g., a programmable processor, a computer, or multiple processors or computers.

The processes and logic flows described in this specification can be performed by one or more programmable processors executing one or more computer programs to perform functions by operating on input data and generating output. The processes and logic flows can also be performed by, and apparatus can also be implemented as, special purpose logic circuitry, e.g., an FPGA (field programmable gate array) or an ASIC (application specific integrated circuit).

The term “data processing apparatus” encompasses all apparatus, devices, and machines for processing data, including by way of example a programmable processor, a computer, or multiple processors or computers. The apparatus can include, in addition to hardware, code that creates an execution environment for the computer program in question, e.g., code that constitutes processor firmware, a protocol stack, a database management system, an operating system, or a combination of one or more of them. Processors suitable for the execution of a computer program include, by way of example, both general and special purpose microprocessors, and any one or more processors of any kind of digital computer.

Computer readable media suitable for storing computer program instructions and data include all forms of nonvolatile memory, media and memory devices, including by way of example semiconductor memory devices, e.g., EPROM, EEPROM, and flash memory devices; magnetic disks, e.g., internal hard disks or removable disks; magneto optical disks; and CD ROM and DVD-ROM disks. The processor and the memory can be supplemented by, or incorporated in, special purpose logic circuitry.

When introducing elements of the present disclosure or exemplary aspects or implementation(s) thereof, the articles “a,” “an,” “the” and “said” are intended to mean that there are one or more of the elements.

The terms “comprising,” “including” and “having” are intended to be inclusive and mean that there may be additional elements other than the listed elements.

While the foregoing is directed to implementations of the present disclosure, other and further implementations of the disclosure may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow. 

1. A web tension adjustment unit for guiding a web, the web tension adjustment unit, comprising: a first guide roller, wherein the first guide roller, comprises: an adjustment unit; one or more first non-contact sensors positioned to measure displacement data of the web at a first location; and a system controller for controlling the adjustment unit based on the measured displacement data.
 2. The web tension adjustment unit according to claim 1, wherein the one or more first non-contact sensors are selected from confocal laser sensors, triangulation based laser sensors, line based laser sensors, capacitance sensors, eddy current sensors, or a combination thereof.
 3. The web tension adjustment unit of claim 1, wherein the one or more first non-contact sensors include at least two sensors arranged in a transverse direction across the web perpendicular to a travel direction of the web.
 4. The web tension adjustment unit of claim 3, wherein the first location is between the first guide roller and a second roller, where the web is in a free span position.
 5. The web tension adjustment unit of claim 4, wherein the one or more first non-contact sensors measure an angle of reflection of the web.
 6. The web tension adjustment unit of claim 1, further comprising one or more second non-contact sensors positioned opposite the one or more first non-contact sensors to monitor cross-web tension to monitor a second side of the web at the first location.
 7. The web tension adjustment unit of claim 1, wherein: the adjustment unit is positioned at a first end of the first guide roller; the adjustment unit comprises a motor; or a combination thereof.
 8. The web tension adjustment unit of claim 1, wherein the system controller is a closed-loop controller, and the measured displacement data is used as variable feedback signal.
 9. A web processing apparatus, comprising: at least one web tension adjustment unit for guiding a web, the web tension adjustment unit, comprising: a first guide roller, wherein the first guide roller, comprises: an adjustment unit; one or more first non-contact sensors positioned to measure displacement data of the web at a first location; and a system controller for controlling the adjustment unit based on the measured displacement data.
 10. The web processing apparatus of claim 9, further comprising a coating unit for coating the web.
 11. The web processing apparatus of claim 9, wherein the one or more first non-contact sensors are selected from confocal laser sensors, triangulation based laser sensors, line based laser sensors, capacitance sensors, eddy current sensors, or a combination thereof.
 12. The web processing apparatus of claim 9, wherein: the one or more first non-contact sensors include at least a first sensor and a second sensor arranged in a transverse direction across the web perpendicular to a travel direction of the web; and the first location is between the first guide roller and a second roller, where the web is in a free span position.
 13. The web processing apparatus of claim 12, wherein the first sensor is positioned to measure displacement of the web at the first location along the transverse direction and the second sensor is positioned to measure displacement of the web at a second location along the transverse direction.
 14. The web processing apparatus of claim 9, wherein: the one or more first non-contact sensors measure an angle of reflection of the web; and the system controller is configured to calculate a signal for adjusting a position of the first guide roller based on the measured angle of reflection of the web such that, after adjustment, the tension of the web on both sides is identical.
 15. A method for processing a web, comprising: guiding the web using at least one web tension adjustment unit, wherein the web tension adjustment unit comprises: a first guide roller comprising an adjustment unit; and one or more first non-contact sensors positioned to measure displacement of the web at a first location; measuring the displacement of the web at the first location to provide measured displacement data of the web; and adjusting a position of the first guide roller by moving one end of the first guide roller, wherein adjusting is based on the measured displacement of the web.
 16. The method of claim 15, further comprising calculating a signal for adjusting the position of the first guide roller based on the measured displacement data of the web, wherein after adjustment, the tension of the web on both sides is identical.
 17. The method of claim 15, further comprising coating the web with a layer of material after adjusting the position of the first guide roller.
 18. The method of claim 15, wherein: the one or more first non-contact sensors are selected from confocal laser sensors, triangulation based laser sensors, line based laser sensors, capacitance sensors, eddy current sensors, or a combination thereof; the one or more first non-contact sensors comprises at least a first sensor and a second sensor arranged in the transverse direction across the web perpendicular to a travel direction of the web; or a combination thereof.
 19. The method of claim 18, wherein: the first location is between the first guide roller and a second roller, where the web is in a free span position; and the first sensor is positioned to measure displacement of the web at a first location along the transverse direction and the second sensor is positioned to measure displacement of the web at a second location along the transverse direction.
 20. The method of claim 15, wherein: the one or more first non-contact sensors measure an angle of reflection of the web; and the method further comprises calculating a signal for adjusting the position of the first guide roller based on the measured angle of reflection of the web, wherein after adjustment, the tension of the web on both sides is identical. 